What is OPPC fiber optic cable ?
L’OPPC (Opticalphase Conductor, or OPPC for short) is a new type of special fiber optic cable for power communication systems. This type of optical cable integrates an optical fiber unit into the traditional phase conductor structure. It fully utilizes the resources of the power system lines, in particular the electricity distribution system.
OPPC optical cables avoid conflicts with the outside world in terms of frequency resources, routing coordination and electromagnetic compatibility. They give optical cables a dual function of transmission of electrical energy and communication.
OPPC is a special optical fiber cable for electric power. In low and medium voltage electrical networks, especially for distribution lines below 35 kV, some of them cannot be grounded, so it is not possible to install the OPGW. In all electrical networks, only the phase line is essential. To meet the requirements of energy monitoring or fiber optic networking, OPPC gets closer to OPGW technology. By adding optical fiber units to the conventional phase line structure appropriately, we obtain a fiber optic composite phase line.
Structure of the OPPC
OPPC cable is mainly made of stainless steel tube, of a fiber optic unit, an aluminum-coated steel wire and a duralumin wire. There are two structural forms : the central tube and the strand.
Due to the unique structure of the fiber optic bundle inside the conductor, OPPC must be installed with pre-tensioned fittings to protect the fiber. There are three advantages to using pre-stranded fittings :
1）easy and quick construction. Workers don't need to pull the heavy compressor, crimping pliers, etc. on the premises, which reduces labor efficiency and physical labor ;
2）Pre-stranded wire fittings are good conductors, good conductivity, a remarkable energy saving effect ;
3）Pre-stranded wire fittings installed in the line and the contact area of the conductor increases, the length of the increase also makes the force of the driver more uniform. This reduces wire fatigue, extends wire life and improves anti-vibration ability.
Structural features
OPPC cable adopts seamless stainless steel tube for optical fiber protection. The tube is filled with imported fiber pulp, which effectively protects the optical fiber ;
Optical fiber in stainless steel tube can get better residual length ;The inner layer of aluminum-clad steel wire mainly plays a role in the tensile strength of the cable ;
The main role of the outer layer of aluminum wire is to ensure the current carrying capacity of the line, but also to provide part of the mechanical resistance ;
According to different conditions of the line, the combination of aluminum clad steel wire and aluminum wire specifications and ratios in the cable can be achieved to meet the requirements of different mechanical properties and electrical conditions.
OPPC Cable Features
1. The design OPPC optical cables suitable for any new medium and low voltage transmission line network.
2. The structure of OPPC optical cables is similar to that of OPGW. However, due to his role as driver, OPPC is used for continuous transmission of electricity.
3. One or more traditional transmission line wires are replaced by fiber optic stainless steel tube units, which are twisted with steel wires (aluminum sheathed), aluminum wires (alloy) to form the OPPC.
4. Replace one phase of three-phase electrical systems with OPPC, forming a transmission line composed of two conductors and an OPPC. When replacing a phase of three-phase electrical systems with OPPC, it is necessary to ensure a performance match. The mechanical and electrical characteristics of the OPPC must be consistent with the two adjacent conductors, such as DC resistance or similar impedance to adjacent conductors, to ensure that three-phase voltage balance is maintained at the remote end.
5. OPPC installed in high voltage systems requires that the accessories and fixings used (such as hanging clips, suspension clamps and terminal junction boxes) are isolated. Clamps can be insulating suspension chains or matching insulating suspension assemblies, while the isolation, optoelectronic separation and connection requires special technical skills, which makes the construction requirements relatively high.
6. Continuous heat resistance : OPPC temperature cycling and current flow tests have demonstrated that they meet constant temperature maintenance requirements.
Benefits
1. Installing OPPC optical fibers within phases optimizes transmission line design, resulting in significant energy savings.
2. Elimination of the risk of serious accidents such as ruptures of conductors and fibers caused by lightning on ground lines ; improved operational safety of cables.
3. Excellent profitability.
4. Elimination of incidents such as electrical corrosion or fiber breaks caused by the effect of the electric field on optical cables.
5. High security system.
6. Absence of risks associated with additional overloading of existing lines.
7. Natural protection against theft : the presence of high voltages on OPPC cables and junction boxes gives an absolute advantage in terms of theft prevention.
Applications
OPPC optical cables are cables where the optical fiber units are composite in phases, giving them a dual function of electrical conductor and communication. They are mainly used on power lines with voltages lower than 110 kV, such as urban periphery distribution networks and rural electricity networks.
1. Due to factors such as power outages and security, they are mainly used on new lines or to replace existing transmission lines requiring ground line replacement.
2. OPPC optical cables are used in medium and low voltage transmission lines without ground line, such as transmission systems 10 kV, 35 kV, 66 kV, etc.
3. In medium and low voltage electrical networks, particularly in the distribution lines of 35 kV and less, some line sections may not require a ground line and use OPPC optical cables.
4. They are used on transmission lines with a single ground line but which cannot be replaced by OPGW cables.
5. They are not suitable for transmission lines where the installation of OPGW and ADSS cables is not appropriate.
Application characteristics of OPPC
OPPC is a composite product of aerial conductors and optical communication. Its maximum optical fiber capacity can reach 144 fibers.
Installation of composite fiber optic cables (OPPC) is essentially similar to that of OPGW, following safety standards and operational techniques of the electrical industry such as IEEE Std 1138-1994 et l’IEEE Std 524-1992. However, OPPC connections involve optical fiber splicing and optoelectronic separation technologies, with strict requirements for high voltage connection and insulation.
The mechanical and electrical characteristics of the cables are well suited to the overhead conductors of the same line, which facilitates design and installation.
OPPC cables are capable of supporting high loads and long span operating requirements.